Currently known terminals for enameled electric wires are constituted by a plate-like body which forms a connection fork with tabs which cantilever inward on the same plane of arrangement as the plate-like body; the tabs face each other so as to form a tapering self-centering opening for guiding the insertion of an electric wire with insulating enamel, said wire being arranged between the ends of the tips of the tabs and an abutment formed on the plate-like body proximate to the tips, with an axis arranged transversely with respect to the arrangement of the plate-like body; the tips form a slot whose transverse dimensions are smaller than the diameter of the enameled wire, so as to cut through at least its insulating layer during its passage between them and provide the electrical contact at the flat part of the ends of the tips.
Such terminals are applied particularly but not exclusively in the wiring of the windings of electric motors and transformers, electric coils, reactors, actuators and power supplies.
Currently, due to the increase in the cost of copper, enameled conducting wires made of aluminum are increasingly widespread.
However, aluminum is softer than copper, and the passage of an enameled aluminum wire between the cut-through tips of a terminal of a known type often causes only the deformation of the aluminum core of the enameled wire, reducing the resisting cross-section, without however cutting through the insulating covering layer; when this occurs, electrical contact between the conducting wire and the terminal does not occur, and the provided electrical connection is substantially unusable.